One type of solid-state image sensor is a charge-coupled device (CCD) image sensor which, in general, comprises a substrate of a semiconductor material having therein an array of photodetectors, such as photodiodes, arranged in one or more lines with a CCD shift register extending along each line of the photodetectors. Each of the CCD shift registers comprises a channel region in the substrate extending along and spaced from the line of photodetectors and a plurality of gate electrodes extending across and insulated from the channel region. Transfer means is provided for transferring photogenerated charge, i.e., electrons, from the photodetectors to the channel of its respective CCD shift register. The CCD shift registers transfer the electrons to an output circuit of the CCD image sensor. Other types of solid-state image sensors are similar except they use other types of shift registers, such as MOS capacitor arrays.
In some applications of the solid-state image sensor it is desirable to be able to halt operation at any time, i.e., reset the device and then resume normal operation. However, present solid-state image sensors do not have the ability to be easily reset during operation, particularly the charge transfer regions, i.e. the shift registers and transfer regions between the photodetectors and the shift registers. Thus, present devices must be operated completely through a clocking cycle prior to resuming operation.